Signature stitcher interrupter apparatus

ABSTRACT

In an apparatus for stitching signatures, an interruptable signature stitching means comprising a drive means operatively connected to an interrupting means which is operatively connected to a stitching head means to selectively actuate said stitching head means, said interrupting means being adapted to selectively interrupt the stitching action of said stitching head means when the thickness of said signatures varies from a predetermined value.

ite States Patent Linden 11 3,747,24 1451 July 24,1973

SIGNATURE STITCHER INTERRUPTER APPARATUS lnventor: Gosta R. Linden, Park Ridge, NJ.

North American Rockwell Corporation, Pittsburgh, Pa.

Filed: July 28, 1971 Appl. No.: 166,732

Assignee:

1111. C1 B2lj 15/28 Field of Search 227/3; 112/21, 22; 270/53-56, 37

References Cited UNITED STATES PATENTS 6/1965 McCain et a1. 270/56 1,644,192 10/1927 Kast ..270/56X Primary Examiner-Robert W. Michell Assistant Examiner-L. R. Oremland Att0mey-.lohn R. Bronaugh et al.

[57] ABSTRACT In an apparatus for stitching signatures, an interruptable signature stitching means comprising a drive means operatively connected to an interrupting means which is operatively connected to a stitching head means to selectively actuate said stitching head means, said interrupting means being adapted to selectively interrupt the stitching action of said stitching head means when the thickness of said signatures varies from a predetermined value.

3 Claims, 6 Drawing Figures PATENTEDJULZMHTS SHEEI 1 OF 4 Fig .6.

mvzmon Gosh: R. Lindon PATENIED JUL 24|973 SHEET Q (If 4 mvzmon Gosm R. Linden SIGNATURE STITCIIER INTERRUPTER APPARATUS BACKGROUND OF THE INVENTION This invention relates to a signature machine in which books are formed from individual juxtaposed signatures, and more particularly to an apparatus for interrupting the stitching or stapling operation of the signatures.

In a signature machine of the kind under construction, individual signatures and folded forms are stapled at a stitching station to join the signatures to complete a book. Usually, it is not desired to stitch defective groups of signatures departing from a prescribed thickness such as a too thick or too thin group of signatures. Thus, it becomes necessary to interrupt the operation of the stitching head which forms and drives the staples into the assembled signatures. It is preferable to interrupt stitching without affecting the normal feed of the signature groups through the stitching station.

Heretofore, the preventing of a stitching operation was accomplished by operation of a clutch mechanism to interrupt the drive to prevent the stitching head and wire staple feeding device from forming and driving the staple into the group of too thin or too thick signatures. The stopping and starting of the drive used to reciprocate the stitching head, operating at high speed, resulted in severe wear of theclutch mechanism and a high maintenance cost for the clutching mechanism. Also, the elements of the machine were subject to shock from the stopping of the momentum of the moving elements. In addition, the stopping operation generated excessive noise.

It has also been suggested that stitching can be prevented by interrupting the feeding of wire to the stapler head in response to a thickness sensing signal from a caliper signal of the approach of a group of signatures having an improper thickness. However, it is necessary to effect costly modifications to existing standard stapling head and wire feeding devices to achieve a wir feeding interrupter capability.

Accordingly, an object of the present invention is a new and improved apparatus for preventing a stitching operation to signatures of improper thickness during a subsequent cycle of the machine by disengaging a con trol lever for the stitching head from operative connection with a machine driven connecting rod without having to interrupt the connecting rod drive means during disengagement or reengagement of the control lever.

It is yet another object of this invention to provide stitching head interrupter apparatus which can be used without modification of existing standard type stapler heads and wire feeding devices.

It is a further object of this invention to effect an interruption of stitching head drive during a period of the machine cycle when the stitching drive has a low momentum to avoid excessive shock, vibration and noise.

SUMMARY OF'THE INVENTION An interruptable signature stitching assembly capable of being used with a signature stitching apparatus comprises a drive means operatively connected to an interrupting means which is operatively connected to a stitching head means to selectively actuate the stitching head means. The interrupting means is adapted to selectively interrupt the stitching action of said stitching head means when the thickness of the signature varies from a predetermined value.

DESCRIPTION OF THE DRAWINGS Other features of the invention will become apparent from the following more detailed description and from the accompanying drawings, in which:

FIG. 1 is a side elevational view of a portion of the stitching machine showing the signatures being conveyed past a thickness sensing caliper to a wire stitching head station;

FIG. 2 is an inlarged plane view of the thickness sensing caliper device shown in the machine of FIG. 1;

FIG. 3 is a fragmentary front elevation of the stitcher station of FIG. 1 showing details of the interruptable signature stitching apparatus with drive means and interrupter means in an upstroke position;

FIG. 4 is a fragmentary front elevation similar to FIG.

3 showing the position of parts of the stitching head drive means and interrupter means near the end of a downstroke position;

FIG. 5 is a fragmentary front elevation similar to FIGS. 3 and 4 showing the position of parts of the stitching head drive means and interrupter means at the lowest portion of the downstroke position; and

FIG. 6 is a fragmentary side sectional view of the parts of the stitching head drive means and interrupter means taken along the line 6-6 of FIG. 3.

DESCRIPTION OF THE INVENTION Referring to the accompanying drawings in which like numerals indicate like parts throughout the several views,'the numeral 10 designates generally a signature being stitched, i.e., having wire staples driven through their folds by stitching heads 14 coacting with staple clincher boxes (not shown) located beneath the apex of the saddle in line with the stitching heads. The number of stitching heads used ordinarily depends upon the length of the book being stitched and the desired bound strength of the book.

The stitching station or location is established by the location of the automatic wire stitching heads 14 of which only two are shown in FIG. 1. One commercially available automatic stitching head which may be used is that sold under the trademark Acme. Each stitching head is fed with a supply of wire W and has a mechanism whereby as the head operates the wire is automatically fed downwardly, one stitch or staple length at a time, and the length is cut and formed into a staple which is driven into the article, to be stitched, by way of its legs, the latter then being clinched.

As indicated in FIG. 3, an eccentric 22 is nonrotatably mounted on a drive shaft 24. Eccentric 22 nonrotatably mounts a connecting rod 26. These components form a drive means used to reciprocally drive a stitching head actuating bar 16. As in conventional, bar 16 is operatively connected to a plurality of individual stitching heads 14. A selectively operable interrupter means'including a slotted support member 28, movable keying member 38, control lever 62 and mounting levers l8 operatively connect the previously explained drive means with the actuating bar 16. A plurality of levers 18 (only one of which is shown) mounts bar 16.

Slotted support member 28 is a four sided rectangular block secured to the top of connecting rod 26 for movement therewith. As best shown in FIGS. 3 and 6, a rectangular slot 30 extends through the block from the center of the blocks front side 32 to the corresponding parallel rear side. A second rectangular slot 34, longer than slot 30, extends through the block from the center of the blocks right side 36 to its corresponding parallel left side.

Movable member 38 is mounted for pivotal movement in slot 34 by being nonrotatably attached to pivot pin 40. Pivot pin 40 is joumaled for rotation within the lower portion of the front and rear sides of block 28 at a level above the lower extremity of slot 34. As best seen in FIG. 6, one end of pivot pin 40 extends outwardly of the block. A collar 43 is attached to the outwardly extending end of pivot pin 40. A lever arm 42 is rigidly attached at a right angle to an end of a collar 43. Lever arm 42 is shown extending to the left in FIGS. 3-5. As best seen in FIG. 6, a small roller 46 is attached for rotation on a fixed stud shaft 44 mounted to the free end of lever 42. Pivotal member 38 is biased in a counterclockwise direction by a small spring 48 terminating at one end about a fixed pin 50 and at its other end to lever 42. Pin 50 is fixedly mounted at the lower end of the block 28.

Referring to FIGS. 3-5, it may be seen that member 38 has its upper end 52 shaped as a slightly curved convex camming crown. Extending through rectangular slot 30 is a pin 54. The ends of pin 54 are rounded while the portion of the pin within the slot 30 is of square cross section. This square cross section of pin 54 has a width slightly less than the width of slot 30 to allow pin 54 to slide vertically in slot 30. As best seen in FIG. 6, the length of the pin 54 which passes through slot 34 has a concave camming recess 56 along its bottom side. The concave camming surface 52 of member 38 lies directly beneath the camming recess 56 and coacts with the pin 54 to support the pin from dropping to the bottom of slot 30.

The ends of pin 54 are rotatably joumaled in yoke arms 58 and 60 respectively which extend on either side of block 28. These yoke arms and pin 54 form a pivotal connection of a control lever 62 with block 28. Non-rotatably attached to the other end of the control lever 62 is a shaft 64. Shaft 64 is joumaled to rotate in one end of supporting arms 65 (only one of which is shown) which arms are pivotally attached to frame structure. Mounting levers 18 are nonrotatably mounted on shaft 64 and move therewith.

Referring to FIG. 6, long spring 66 is shown attached at its one end to an extension of pin 54. The other end of spring 66 is attached to frame supporting structure (not shown). Spring 66 acts as a means for biasing control lever 62 in a clockwise direction as viewed in FIG. 3.

The cycle of operation of the interruptable signature stitching means described above is as follows: Shaft 24 rotates cam 22 to the position shown in FIG. 3. This moves connecting rod 26 with block 28 mounted thereon to the highest position of its reciprocating path. Since pivotal member 38 supportingly engages pin 54, the control lever 62 is drivingly engaged by block 28 and pivots shaft 64. Rotation of shaft 64 in turn rotates mounting levers l8 counterclockwise which moves actuating bar 16 to thereby cause stitching heads 14 to stitch a group of signatures S cyclically advanced to the stitching station.

In a preferred form, substantially at the moment the block 28 reaches the high point in its oscillatory path shovm in FIG. 3, a group of signatures is passing through a signature thickness sensing caliper device located to the right in FIG. 1. The particular caliper device 65 shown in FIG. 2 is a commerically available mechanical caliper. The present invention is not to be construed as limited to the particular type calipering device 65 shown for purposes of illustration as other known mechanical or electromechanical sensing devices, such as for example, a betta ray gauge, are readily employed with the present invention.

The general operation of caliper device 65 is as follows: A calipering wheel segment 67 is driven by a gear train 69 composed of gears 69a, 69b, 69c and 69d. Wheel segment 67 is mounted for rotation on the same shaft as gear 69a which shaft is joumaled for rotation in a lever arm 70 and a shorter rear lever arm 70a attached to lever arm 70. Lever arm 70 pivots freely about a shaft 71 securely attached at one end to a stationary support plate behind the lever arm. Fixed shaft 71 mounts freely rotatable idler gear 69b. Gears 69a and 69b are mounted between lever arm 70 and shorter rear arm 70a. Fixed shaft 71 extends through rear arm 70a. Gears 69c and 69d are not joumaled on the lever arms 70 and 70a. Machine driven means (not shown) power gear shaft 72 which non-rotatably mounts drive gear 69d. The forward end of shaft 72 extends through an opening in lever arm 70 but does not contact the lever arm. Gear 69c acts as an idler gear intermeshing with gears 69b and 69d. Gear 69c is joumaled on a fixed shaft located behind lever arm 70.

A spring 73 attached to an extension of arm 70 and to support structure biases the lever arm 70 in a counterclockwise direction. A cam 74 is non-rotatably mounted on gear shaft 72. Cam 74 is contacted by a roller 75 which is rotatably mounted on a pin 76 which pin is rigidly attached to lever arm 70. Spring 73 acts to bias roller 75 upwardly against the rotating cam 74 which stops the rotation of biased lever arm 70.

An anvil wheel 77 is located a preselected distance beneath caliper wheel segment 67 and is mounted for free rotation about an adjustable eccentric stud 78.

In operation, a group of signatures S is timed to pass between wheel segment 67 and anvil wheel 77 as the wheel segment is rotated through the lower half of its 360 cycle. By adjusting the relative positions of the caliper parts, the surface of wheel segment 67 normally only approaches close enough to anvil wheel 77 to engage a group of signatures S having proper thickness.

If a too thick group is encountered, wheel segment 67 will be raised, thereby rotating lever arm 70 clockwise about shaft 71 against the bias of spring 73. Clockwise rotation of the lever arm will cause a stationary signal generation limit switch 79 mounted adjacent an end of lever arm 70 to be energized.

In order to sense a too thin group of signatures, a depression 80 has been placed in the surface of cam 74. Thus, once while wheel segment 67 is in the signature engaging portion of its cycle, roller 75 is able to move closer to shaft 72. If a group of signatures having a proper thickness is passing between wheel segment 67 and anvil wheel 77, then the wheel segment will already be in engagement with the group of signatures and roller 75 will be unable to move closer to the shaft 72.

However, if a too thin group of signatures is encountered, then wheel segment 67 will move down downwardly by the missing thickness because spring 73 is biasing the lever arm 70 counterclockwise about shaft 7I. Counterclockwise movement of lever arm 70 causes a stationary signal generator limit switch 81 mounted adjacent an end of lever arm 70 to be energized.

Thus, clockwise movement of arm 70 means that limit switch 79 is energized while counterclockwise movement means that limit switch 81 is energized. In this manner an electrical output signal is sent if an incorrect signature group thickness is detected. 8

In the prior art, an incorrect signature thickness signal controlled a powered electric circuit connected with a solenoid which controlled a clutch used to disrupt the stitcher head drive train. The necessary circuit is well known. A corresponding circuit may be used with the present invention to activate a solenoid 82 (FIGS. 3-5). Once activated, solenoid 82 remains energized through a conventional holding circuit (not shown) until a group of signatures having the correct thickness is sensed by the calipering device. Deenergization of the holding circuit occurs when neither of the calipering device limit switches 79 or 81 is activated by a group of signatures following the defective group which triggered the holding circuit.

If the calipering device 65 detects that a group of signatures fails to meet the prescribed thickness as explained above, it causes activation of a blocking means. The blocking means as seen in FIGS. 3-6 includes solenoid 82 mounted on machine frame structure. Solenoid 82 is attached to one end of a reciprocable link arm 83. The other end of link arm 83 is pivotally attached to a blocking cam 84. Blocking cam 84 is rigidly attached at its lower end to pivot shaft 86 which shaft can rotate in bearing means (not shown) mounted to machine frame structure. As shown in FIG. 3, blocking cam 84 is biased in a counterclockwise inoperative position by spring 88. One end of spring 88 is fixed to machine frame structure while the other end is hooked around a stub shaft 90 rigidly mounted in the upper end of the blocking cam 84. A limit stop screw 92 engages the lower end of the blocking cam to limit the counterclockwise position of the blocking cam. Screw 92 is mounted for adjustment in one end of support arm 96 by means of nut 94. Arm 96 is rigidly mounted to machine frame structure.

Activation of solenoid 82 moves link arm 83 to the right to overcome the bias of spring 88 and pivot blocking cam 84 clockwise into an operative position. This movement of blocking cam 84 occurs when connecting rod 26 is in the general upstroke position shown in FIG. 3.

As shown in FIG. 4, upon downward reciprocation of the block 28 by the eccentric cam 22, the cam follower roller 46 mounted on lever arm 42 strikes the blocking cam 84. Movement of lever arm 42 causes clockwise rotation of pivotal member 38 out of supporting engagement with pin 54. Once the member 38 is re moved, the top of slot 30 will pull pin 54 to the position shown in FIG. 5. Spring 66 acts to hold pin 54 in this position. Member 38 is held out of engagement with the pin by the blocking cam 84. In this manner, the operative connection between the block 28, member 38 and control lever 62 is disrupted.

Cam 22 causes block 28 to first accelerate and then decelerate as it nears the positions shown in FIGS. 3 and 5. It is an important feature of this invention that blocking cam 84 is positioned to intercept the path of movement of cam follower roller 46 at a location where the block is decelerating and has almost reached the low position of the downstroke and therefore has low momentum. The shock of contact of the roller 46 against the blocking cam is thus minimized.

After cam follower roller 46 strikes the blocking cam 84, the downward oscillation of the block 28 continues uninterrupted. FIG. 5 shows the position of the parts of the interrupting means and the drive means at the low position of the reciprocation of the block. Pin 54 is now at its lowermost position in which it remains stationary under the pull of spring 66. If it were not for the blocking cam 84 being in the operative position, pivotal member 38, which is now completely out of engagement with pin 54, would be able to pivot back underneath the camming recess 56 of the pin 54 due to the biasing pull of spring 48.

Upon reaching the low position of the downward stroke, the block 28 then repeats its reciprocatory cycle and reverses direction and accelerates upwardly towards the position shown in FIG. 3. However, pin 54 remains stationary as it is disengaged from being drivingly connected to the block. Keying member 38 is pivoted by the spring 48 to rub against the side of the pin 54 as soon as the cam follower roller 46 loses contact with the top of the blocking cam 84. However, this does not occur until after camming surface 52 of member 38 has passed the pin recess 56 as the block 28 moves upwardly.

7 Because the control lever 62 remains stationary, there is no actuation of the stitcher heads 14 as the block 28 reaches the top position of its reciprocatory path. The defective group of signatures previously sensed thus passes beneath the stitching station without being stitched. After passing the stitching station, the defective group is then automatically diverted from the normal path by a conventional routing director mechanism (not shown) which may be activated by the calipering mechanism at the same time the solenoid 82 is activated. It will be recalled that the calipering mechanism senses the thickness of a'group of signatures during the period that the block 28 is in the general position of FIG. 3. If the next group sensed is defective, the holding circuit which activated solenoid 82 will continue to be energized. Thus, upon a downward stroke of said connecting rod 26, member 38 would again be prevented from rotating counterclockwise underneath the camming recess 56 as the cam follower roller 46 would again contact the top surface of the blocking cam 84.

However, when a group of signatures is sensed which meets the prescribed thickness, neither limit switch 79 or 81 is energized which causes the conventional holding circuit to become deactivated thereby deenergizing solenoid 82. This allows spring 88 to pivot the blocking cam counterclockwise about the axis of pivot shaft 86 to the inoperative non-contacting position shown in FIG. 3.

Upon the block 28 approaching the low position of its downward stroke, the convex camming surface 52 of the member 38 can rotate counterclockwise beneath the camming recess 56 of pin 54. At this point, the stationary-pin 54 is close enough to the top of slot 30 to allow clearance of the member 38 beneath it. Since the blocking cam 84 is now in the inoperative position, spring 48 is effective to automatically move member 38 into a position of driving engagment with the pin 54.

In operation, connecting rod 26 can achieve a predetermined rate of oscillation of over 200 cycles per minute. With the above selectively operable interrupter means, it is possible to prevent stitching without interrupting the normal oscillating path of cam driven connecting rod 26 and the block 28 mounted thereon. By timing the engagement and disengagement of pivotal member 38 and pin 54 to occur near the end of one of the reciprocatory strokes when the mass of moving parts is decelerating and has a low momentum, the excessive shock, noise and wear of parts are minimized.

A further significant advantage of the present invention is that no adjustments need be made when the speed of operation of the stitching heads is altered for a different run of signature groups. This is due to the fact that blocking cam 84 need only be timed to move to the operative position prior to the arrival of cam follower roller 46 to this position during the downward stroke. Provided the block cam is in the inoperative position, member 38 will always be pivoted underneath the camming recess 56 just prior to the block 28 reaching the low position when reengagement is desired. Movement of the blocking cam to the inoperative position need only occur prior to the block 28 reaching the position shown in'FIG. 4.

It is to be understood that the above detailed description of the present invention is intended to disclose an embodiment thereof to those skilled in the art, but that the invention is not to be construed as limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of being practiced and carried out in various ways without departing from the spirit of the invention. The language used in the specification relating to the operation and function of the elements is employed for purposes of description and not of limitation, and it is not intended to limit the scope of the following claims beyond the requirements of the prior art.

I claim:

1. In a signature stitching apparatus, the combination comprising:

a stitcher head mounted for reciprocation between a stitching position and a retracted position;

a pivotally-mounted lever having a first arm thereof connected to the stitcher head;

drive means for oscillating said lever whereby to reciprocate said stitcher head between said positions including a continuously driven crank means;

a block member connected to said crank means and having an elongated slot formed therein, said slot being substantially equal in length to the throw of said crank means;

a second arm of said lever;

a drive pin carried by said second arm and having a sliding fit in said elongated slot;

a control member pivotally mounted on said block for movement between a drive position wherein it locks said pin at one end of said slot to thereby transmit the motion of said crank means to said lever and stitcher head and a drive interrupt position wherein it releases said pin for free sliding motion in the elongated slot; sensing means for detecting the presence of an improper signature to be stitched; and, trip means responsive to said sensing means upon the detection of an improper signature for moving said control member to the drive interrupt position. 2. A signature stitching apparatus as set forth in claim 1 further including resilient spring means connected to the said second arm of said lever for biasing the stitcher head in its retracted position upon movement of said control member to its driven interrupt position.

3. A signature stitching apparatus as set forth in claim 1 wherein said trip means comprises a cam lever on said control member, a pivotally mounted blocking cam having an inoperative position wherein it is clear of said cam lever and a tripping position wherein it intercepts said cam lever, resilient spring means for biasing the blocking cam to its inoperative position, and means responsive to said sensing means for moving the blocking cam to its tripping position upon the detection of an improper signature.

a k k s 

1. In a signature stitching apparatus, the combination comprising: a stitcher head mounted for reciprocation between a stitching position and a retracted position; a pivotally-mounted lever having a first arm thereof connected to the stitcher head; drive means for oscillaTing said lever whereby to reciprocate said stitcher head between said positions including a continuously driven crank means; a block member connected to said crank means and having an elongated slot formed therein, said slot being substantially equal in length to the throw of said crank means; a second arm of said lever; a drive pin carried by said second arm and having a sliding fit in said elongated slot; a control member pivotally mounted on said block for movement between a drive position wherein it locks said pin at one end of said slot to thereby transmit the motion of said crank means to said lever and stitcher head and a drive interrupt position wherein it releases said pin for free sliding motion in the elongated slot; sensing means for detecting the presence of an improper signature to be stitched; and, trip means responsive to said sensing means upon the detection of an improper signature for moving said control member to the drive interrupt position.
 2. A signature stitching apparatus as set forth in claim 1 further including resilient spring means connected to the said second arm of said lever for biasing the stitcher head in its retracted position upon movement of said control member to its driven interrupt position.
 3. A signature stitching apparatus as set forth in claim 1 wherein said trip means comprises a cam lever on said control member, a pivotally mounted blocking cam having an inoperative position wherein it is clear of said cam lever and a tripping position wherein it intercepts said cam lever, resilient spring means for biasing the blocking cam to its inoperative position, and means responsive to said sensing means for moving the blocking cam to its tripping position upon the detection of an improper signature. 